Contour crutch



p 1964 A. J. JOHNSON, JR 3,150,672

couroua CRUTCH Filed Dec. 4, 1961 INVENTOR. ARTHUR J. JOHNSON. JR.

k ATTORNEY.

United States Patent 3,150,672 CONTOUR CRUTCH Arthur J. Johnson, Jr.,Mount Vernon, N.Y., assignor to Johnson Therapeutical Corp., New York,N.Y., a corporation of New York Filed Dec. 4, 1961, Ser. No. 156,883 2Claims. (Cl. 135-52) This invention relates to a new principle in theconstruction of crutches whereby a crutch head contour is provided whichembraces both the rib cage and the arm of the user to stabilize thecrutch.

Heretofore, the conventional crutch head contour has provided only anupward curvature having its radii of curvature lying substantially in avertical plane, so that the crutch head will embrace the arm pit whenthe body weight is allowed to rest downwardly on the head of the crutch.

However, this traditional construction overlooks the important fact thatin walking with crutches, the body weight is periodically borne by thehands acting on the crutch handles so as to lift the armpits clear ofthe crutch head contour. This action allows the crutch to pivot untilthe upwardly curved contour of the conventional crutch head strikeseither the front or back of the shoulder, resulting in the familiarabrasion and discomfort heretofore suffered by crutch users.

The present invention overcomes this objectionable instability byproviding a contour of crutch head having two curvatures in thehorizontal plane, one of which embraces a portion of the cylindricalcontour of the rib cage and the other of which embraces a portion of thecylindrical contour of the arm.

This novel geometry in effect provides a Vertical keyway so that,contrary to the normal vertically reciproeating displacement of thecrutch head into and out of the arm pit in the act of walking withcrutches, the crutch head of this invention remains keyed to the body,providing the stabilizing moment necessary to prevent the hands andwrists from bearing the reaction torques of crutch Walking and toprevent flailing against the body by the crutch head.

It is the principal object of the present invention to provide a crutchconstruction affording superior comfort and convenience in use.

and superior in performance.

It is still another object of the invention to provide a crutch headcontour which embraces the body regardless of displacement of the crutchhead away from the arm pit.

It is a further object of the invention to provide in a crutchconstruction, the combination of an adjustable crutch handle and acrutch head contoured partially to embrace both the rib cage and thearm.

It is still a further object of the invention to provide a crutch headcontour having its radii of curvature lying substantially in a planenormal to the long axis of the crutch.

For other objects and a better understanding of the invention, referencemay be had to the following detailed description taken in connectionwith the accompanying drawing, in which FIGURE 1 is a plan view of thecontour of the preferred embodiment of the crutch head invention,showing the outer flexible covering broken away to reveal a layer ofresilient padding, and showing the padding broken away to show the bodyof the crutch head.

FIG. 2 is a broken view taken in elevation of a crutch incorporating theinvention as viewed on line 2-2 of FIG. 1,

v ,7 3,150,672 Patented Sept. 29, 1964 "ice FIG. 3 is a frontperspective view of the contour crutch showing its relation to the userduring the act of walking,

FIG. 4 is a back perspective view of the contour crutch showing thedoubly embracing action of the crutch head contour relative to the bodyof the user, and

FIG. 5 is a plan view cross section of the contour crutch taken on line55 of FIG. 3.

Referring now to the drawings, it may be seen that the crutch head ofthe preferred form of the invention consists of a body 1, preferably ofwood, covered by a resilient padding 2 such as sponge rubber, over whichis secured a flexible outer covering 3, which may be leather or plastic.

The inner vertical surface 10 is contoured to fit the average contour ofthe rib cage, and is shown to have a single radius of curvature R lyingin a horizontal plane normal to the long axis of the crutch. The outervertical surface 11 of the crutch head also has a concave contour to fitthe average contour of the arm, and is shown to have a single radius ofcurvature R also lying in a horizontal plane normal to the long axis ofthe crutch.

It is to be noted that although the conventional upwardly curvedcontour, having its radii of curvature in a vertical plane lying in thelong axis of the crutch, has been omitted in the drawings asunnecessary, it is within the scope of the invention to add thisvertical contour in addition to the horizontal curvatures shown.

The crutch head body 1 is secured, preferably by keying and adhesives,to the vertical side support members 4 and 5 which merge to form thefoot 12 of the crutch. A non-skid ferrule 13 is provided on the foot 12.

Foot 12 may also be provided with any of the adjustable length featureswell known in the art.

In order that the keyed horizontal contour of the crutch head be able toslide properly against the body under the lateral constraint of the armand rib cage, it is important that the user grasp the crutch handle 6 ata distance from the crutch head such that, with the arm straightened,the top of the crutch head not be seated in the arm pit. For thisreason, and as a cooperating part of this crutch, the handle 6 isprovided with disengageable pins 14 and 15 which may be engaged by thespreading of members 4 and 5, with any pair of a plurality of spacedpairs of socket holes 7, 7', 8, 8', 9, 9' piercing members 4 and 5 so asto provide an adjustment between the position of handle 6 and the doublycurved crutch head 1.

The front and rear views of FIGS. 3 and 4 respectively, are drawn toshow the moment in walking with the crutch at which the body weight islargely supported by the hand thereby straightening the arm and drawingthe arm towards the body. Under these circumstances, and as seen in theplan cross section of FIG. 5, the two concave surface contours 10 and 11are firmly clamped against fore and aft motion between the rib cage andarm respectively.

It should now be apparent that this clamping action is widelyindependent of contact between the top of the crutch head and the seatof the arm pit.

In contradistinction to the foregoing, the fore and aft clamping actionof the conventional vertically curved crutch head immediately diminishesand disappears as soon as any vertical clearance takes place between theseat of the arm pit and the top of the conventional crutch head.

While various changes may be made in the detailed construction, it shallbe understood that such changes shall be within the spirit and scope ofthe present invention as defined by the appended claims.

What is claimed is:

1. In a crutch, spaced vertical side support members merging into a footat the bottom end thereof, a handle adjustably mounted between said sidesupport members at an intermediate location therealong, and a crutchhead secured to the top end of said support members at a point normallysubstantially below the arm pit of the user, said crutch head includingan elongated body with a wide radius concave surface on one side thereofextending substantially the length of said crutch head body, contouredto substantially embrace the rib cage of the user, and with a convexsurface on the other side thereof, said convex surface having a concaveportion centrally thereof of a radius substantially less than that ofsaid first-mentioned concave surface contoured to substantially embracethe medial portion of the arm of the user.

2. The structure of claim 1 wherein said crutch head body is coveredwith a resilient padding over which is secured a flexible outercovering.

References Cited in the file of this patent UNITED STATES PATENTS1,197,727 Finkle Sept. 12, 1916 1,311,664 Pearl July 29, 1919 2,362,642Lamb Nov. 14, 1944 2,856,943 Sparlin Oct. 21, 1958 FOREIGN PATENTS972,491 France Aug. 30, 1950

1. IN A CRUTCH, SPACED VERTICAL SIDE SUPPORT MEMBERS MERGING INTO A FOOTAT THE BOTTOM END THEREOF, A HANDLE ADJUSTABLY MOUNTED BETWEEN SAID SIDESUPPORT MEMBERS AT AN INTERMEDIATE LOCATION THEREALONG, AND A CRUTCHHEAD SECURED TO THE TOP END OF SAID SUPPORT MEMBERS AT A POINT NORMALLYSUBSTANTIALLY BELOW THE ARM PIT OF THE USER, SAID CRUTCH HEAD INCLUDINGAN ELONGATED BODY WITH A WIDE RADIUS CONCAVE SURFACE ON ONE SIDE THEREOFEXTENDING SUBSTANTIALLY THE LENGTH OF SAID CRUTCH HEAD BODY, CONTOUREDTO SUBSTANTIALLY EMBRACE THE RIB CAGE OF THE USER, AND WITH A CONVEXSURFACE ON THE OTHER SIDE THEREOF, SAID CONVEX SURFACE HAVING A CONCAVEPORTION CENTRALLY THEREOF OF A RADIUS SUBSTANTIALLY LESS THAN THAT OFSAID FIRST-MENTIONED CONCAVE SURFACE CONTOURED TO SUBSTANTIALLY EMBRACETHE MEDIAL PORTION OF THE ARM OF THE USER.